Engine efficiency and power is a growing concern and has been the subject of various technological advancements in the automotive industry for many years. However, many of these technological advancements do not operate to reduce the torque or energy that is required to turn the camshaft and thereby operate the engine. An improved engine that uses less torque turning or operating the camshaft will result in that power being returned to the crankshaft or other portions of the engine or vehicle for higher power output or higher overall efficiency. It should also be noted that an engine that is more efficient can be built smaller to output the same power as a larger engine.
Accordingly, there is a need in the art for an improved cam or camshaft that would result in less power required to drive the cams or camshaft, thereby resulting in a vehicle and engine with higher efficiency and/or power. The proposed invention relates to a camshaft or an improved cam which can reduce the rotational speed of the camshaft by half, or otherwise cause the camshaft to rotate at one fourth the speed of the crankshaft in a typical four stroke internal combustion engine. This would cause the camshaft to turn one full revolution for every eight strokes of the rotating assembly.
In particular, the proposed invention would include a cam or a plurality of cams with two lobes, disposed approximately one hundred and eighty degree apart on the same base circle. The first lobe would operate a valve, push rod, etc. during one four stroke cycle, followed by the second lobe operating the same valve, push rod, etc. during the next four stroke cycle, and so on.
In order to accomplish this, additional structural characteristics of the cam and lobes need to be modified. For example, the diameter of the base circle of the proposed dual-lobed cam is significantly increased and the duration is reduced in order to maintain a sufficient operational lift.
By slowing the rotational speed of an engine component, such as the camshaft, the component may be turned more easily by using less torque or power, thereby allowing more power to return to or be retained by the output of the engine. This may result in better efficiency and/or more power. For instance, by reducing the gear ration between the camshaft and crankshaft to 4:1, the necessary torque required to turn the camshaft is reduced significantly, and in many cases, by half. Furthermore, if the diameter of the base circle of the cam(s) is increased, a more gradual approach to the acceleration ramps may be used for the lobes, thereby allowing the camshaft to open or displace the valves with less resistance, adding to the efficiency of the engine. Moreover, the slower camshaft speed, combined with the improved lobe design and configuration could cause the valve train to operate in a more stable manner at higher RPMs, and could allow for a lighter valve spring.